While the invention is subject to a wide range of applications, it is especially suited for use with wrist watches and will be particularly described in that connection.
There is increasing interest in the use of digital displays in wrist watches. One popular type of display is composed of light emitting diodes (LED). Such displays are attractive, reliable, and easily read; however, they require appreciable energy for operation. Because the power supply for a wrist watch is quite small, such displays are generally activated by a push button switch. When one is carrying packages or driving a car, the requirement to operate the push button is quite inconvenient and is a definite drawback to the use of such watches.
The use of the position of the human body to energize an electrical circuit has been disclosed in my prior U.S. Pat. No. 3,683,130. In that invention, the position of the head is used to activate a head set which allows one to hear sounds while being protected from high ambient noise. The circuitry in U.S. Pat. 3,683,130 is activated by head position and the system does not rely upon the speed or acceleration of the motion.